... J. LEWIS, Department of Food Science and Technology, The University of Reading, Whiteknights, PO Box 226, Reading, RG6 6AP 1.1 FOODS - THE RAW MATERIAL Food and drink play a vital ... reproduction. Although foods are commonplace and much taken for granted, their composition and structure are by no means simple. Firstly, all foods are chemical in nature. For most foods the principal ... colour changes in foods, particularly browning, and lipoxygenases, which produce rancid off- flavours (Nagodawithana and Reed, 1993). Therefore foods and wastes produced during food processing...